Field of the Invention
One disclosed aspect of the embodiments relates to an image forming apparatus, a method for controlling the image forming apparatus, and a recording medium.
Description of the Related Art
Conventionally, in an image forming apparatus such as a printer, a facsimile apparatus, or a copying machine, predetermined power generated by a power supply device is supplied to a predetermined load of the image forming apparatus. The image forming apparatus includes a power supply control device. If the image forming apparatus does not operate for a certain time period, the power supply control device shifts the image forming apparatus from a normal mode where a user can operate the image forming apparatus to a power saving mode (a sleep mode) for reducing power consumption. However, even if the operation by the user has ended, it is necessary to maintain the normal mode for a certain time period until the image forming apparatus shifts to the sleep mode. This may lead to consuming unnecessary power.
To solve this problem, the following apparatus is discussed. Human body detection units are provided in an image forming apparatus. If the human body detection units detect that a user has moved away, the image forming apparatus shifts to a sleep mode. If the human body detection units detect that a user has approached the image forming apparatus, the image forming apparatus shifts to a normal mode (see Japanese Patent Application Laid-Open No. 2012-256234).
Further, there is also an apparatus for determining a power saving mode to which the apparatus is to shift, according to information of various sensors and start history information (see Japanese Patent Application Laid-Open No. 2009-15770).
In the technique discussed in Japanese Patent Application Laid-Open No. 2012-256234, two human body detection units are used to determine whether a person is a user of the image forming apparatus or a passerby. If, however, a person has stopped in front of the image forming apparatus, the human body detection units may erroneously determine that the person is a user. That is, even though a user intentionally sets the shift to the sleep mode, which is a power saving state, and shifts the image forming apparatus to the sleep mode, if a user who does not intend to use the image forming apparatus merely approaches the image forming apparatus, the image forming apparatus shifts to the normal mode. This may lead to consuming unnecessary power.
Further, in the technique discussed in Japanese Patent Application Laid-Open No. 2009-15770, the power saving state is determined according to the states of the various sensors and the start history information. Thus, a user cannot intentionally specify a power state where the power consumption is small. This may lead to consuming unnecessary power.